Method of enameling centrifugally-cast pipe



J. B. LADD METHOD OF ENAMELING CENTRIFUGALLY CAST PIPE Fil'edNOV. 28, 1922 v ron add;

' ATTORNEY Patented Jan. 6, 1925.

UNITED STATES PATENT orrice.

JAMESB. LADD, OF ARDMORE, PENNSYLVANIA, ASSIGNO'R TO UNITED STATES CAST IRON PIPE & FOUNDRY COMPANY, OF BURLINGTON, NEW JERSEY, CORPORATION OF NEW JERSEY.

METHOD OF ENAMELING CENTRIFUGALL Y-CAST PIPE.

Application filed November 28, 1922. Serial No. 603,758.

To all whom it may concern:

Be it known that I, JAMES B. LADD, a citizen of the United States of America, and residentof Ardmore, county of Montgomery, State of Pennsylvania, have invented certain new and useful Improvements in Methods of 'Enameling Centrifugally-Cast Pipe, of which the following is a true and exact description, reference being had to the accompanying drawings, which form a part thereof.

My invention relates to the manufacture of pipe in rotating molds by the centrifugal process and has for its object to provide an efficient method of applying enamel to the inner surface of such pipes during the casting operation.

Broadly speaking, my invention consists in coating the enamel on the surface of the molten metal while it is still held in the container or trough through which said molten metal is introduced into the rotating mold and pouring the enamel into the-mold to gether with the melted metal. My newly invented method will be best understood as described in connection with the drawings in which I have illustrated a suitable apparatus for carrying out my improved method in what I believe to be its best and most eflicient method 1 of application and in which- Figure 1' is a sectional side elevation,

. through a centrifugal casting apparatus showing in connection therewith means for feeding the enamelinto the trough through which the metal flows into the mold, and

Figure 2 is a cross section on the line 2--2 of'Fig. 1.

The apparatus shown in Fig. 1 embodies features of construction invented by meand forming the subject matter of co-pending applications for Letters Patent, no features of'the apparatus being specifically claimed in this application.

In the drawing, A is the frame supporting the molding apparatus which is preferentially inclined as indicated and which supports tracks indicated at A. B is a casing in which the mold is supported and which forms the outer shell of a'water jacket surrounding the mold, this casing being supported on the tracks indicated at A by wheels indicated at B, B and the casing also having, as shown, a downwardly extending ear B C is a cylindrical casing rotatably supported in the casing B and forming the inner wall of the .water jacket which is indicated at D. provided at its left hand end with a gear wheel indicated at C which, through gears indicated at H, is rotated by a motor indicated at-H. E is the mold proper which, as illustrated, is a sectional mold longitudinally adjustable in the casing C and having, as indicated at E, inclined surfaces which, when the mold is movedv toward the left, engage inclined surfaces on the casing 'C and clamp and hold the sections of the mold together. a F indicates a core piece for the bell end of the pipe which, as shown, is secured in the left hand end of the mold E. G is a. stop secured to the framing A and which, when the casing B carrying the mold with it, moves toward the left, comes incontact with the metal part of the core piece F with the effect that the sectional mold has its motion arrested before the motion of the casing B is arrested. This in effect shiftsthe mold toward the right in the casing, permitting its sections to be moved apart. I is a piston rod secured to the ear B and extending from a piston working in the cylinder I. Pressure fluid is, of course, admitted and exhausted from the ends of the cylinder I through connections, not shown, and the mold moved downward or forward at will. J is a frame supporting, as shown, a bottom pour ladle J. K is an extension of the frame A on which is pivotally-supported the cylindrical extension ,K of a pouring trough indicated at K into which the melted metal flows from the ladle J.

In all of the above briefly described features the apparatus illustrated is of the general character described and so far as I believe it to be new, claimed in my copending applications.

L is a frame supporting a hopper indicated at L intended to contain finely powdered enamoling material and opening into a screw conveyor indicated at L through which the finely powdered enameling material is'fed with regulated speed intothe trough K as shown in Fig. 2, M indicat ing the stream of enamel falling on the metal in the trough K 7 p In operation, the mold having been moved toward the right until the end of the trough This casing is K is at the extreme end of the mold, molten metal is permitted to flow from the ladle J into the trough K and through said trough into the mold, the metal running from the trough into the mold being indicated at N. Shortly after the metal begins to flow from the end of the trough into the mold the mold is given a progressive movement to the left and being in full rotation metal flowing into it from the trough is deposited in the mold in a spiral coil, the contacting portions of the coils fusing together so that with a complete movement of the mold a centrifugally cast pipe is formed in it and with the completion of the casting the flow of metal is cut oil, the casting extracted in any convenient way and subsequently a fresh casting made in the same way as above described.

As the molten metal flows through the trough toward the mold the conveyor L is put in operation and a regulated feed of finely powdered enamel is fed intothe trough K on topof the flowing stream of molten metal therein. The heat of the metal will fuse the enamel but whether fused or partly fused the enamel is evenly distrib uted over the flowing stream of metal and delivered into the mold together with the metal so that it flows into the mold in proportionatequantity to the metal flowing into the mold and is evenly distributed throughout the length of the mold. Owing to the lightness of the enamel with res ect to the melted metal and the centrifuge action of the mold the enamel will remain on the inside of the casting and will be evenly distributed throughout the len th of the casting and it will be understood that the mold must be kept in rotation until both the melted metal and the enamel coating its inner surface have solidified and that the result will necessarily be a smooth and evenly distributed inner coat of enamel, free from such inequalities of surface as are apt to occur where the comparatively thin enamel coating has to flow longitudinally in order to distribute itself throughout the length of the pipe. It is, however, true that my invention can be usefully applied even where a longitudinal flow of the metal and of the I enamel takes place in the rotating mold during the casting operation since the enamel in my method of operation flows into the mold to ether with the melted metal and is distri uted by and with the melted metal in which respect my method is distinctive from methods in which the enamel is introduced into the mold thnou 'h a separate conduit from that through w iich the melted metal flows into it.

Having now described my invention, what I claim as new and desire to secure by Letters Patent, is: r

1. The method of applying enamel to the inside of centrifugally cast pipe which consists in floating the enamel on the surface of the molten metal in the container through which said metal is introduced into the rotating mold and pouring said metal and enamel simultaneously into the mold.

2. In a centrifugal pipe casting process in which the molten metal is run into a rotating mold through a trough the method of applying enamel to the inside of the pipe being cast which consists in feeding enamel in regulated quantity to the metal flowing through the trou h and running it into the mold together with the molten metal.

3. In a centrifugal pipe casting process in which the molten metal is run into a rotating mold through a trough and in. which the rotating mold and the trough are given a relative ongitudinal movement so as to bring about the feeding of the metal to the mold in a progressive spiral, the method of applying enamel to the inside of the pipe being cast which consists in. feedin enamel in regulated quantity to the meta flowing through the trough and running it into the mold together with the molten metal.

JAMES B. LADD.

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